The present invention improves upon the overload release clutch of the type shown in U.S. Pat. Nos. 3,835,973 and 4,220,230, the latter one being my own previous invention. The present invention differs from the prior art in that it is a release clutch which avoids wear commonly induced by the forces which operate to cause the clutch to release. The clutch shown in U.S. Pat. No. 3,835,973 shows and describes only limited relative rotation of the clutch-engaging members which are not disclosed as rotating past each other in either direction of rotation. Further, the engaging members are two separate and relatively radially movable parts which must be provided for in a plurality of parts, rather than only several of one type of a movable part as in the present invention.
Further, the prior art, as in my previous patent U.S. Pat. No. 4,220,230, differs from the present invention in that it requires certain sizing and dimensioning between the respective diameters of a ball and a pin, and they present a point contact between each other, and thus the release torque in that clutch is of a concentrated pressure requiring sturdy parts which normally must be hardened to sustain the wear.
Accordingly, the present invention improves upon the prior art in that it provides for an overload release clutch which withstands release forces, and, upon release the input and output members can be rotated in both directions of rotation, relative to each other, and the release torque can be adjustably set in the clutch and there is only a minimal amount of wear and stress on the clutch parts themselves. That is, where the prior art provides for a point contact in the clutch elements, the present invention provides for a line contact with only one part thereof being a movable part and with that same part being the one which disengages the clutch. Another part then provides for retaining the clutch in the disengaged position until the clutch is re-set to again subject itself to the overload or desired torque condition. As such, the present invention does not require the strength nor hardening of parts, as in the prior art, and the clutch in the present invention is more reliable, sturdy, and durable on its nature as an overload release clutch.